still in SWOT vac

Went to an extra swot vac tute today. really worried for not able to answer/understand 90% of the things mentioned in the tute!! the exam for taht ppr is on 23rd, my last ppr. but remembering that during the first lecture for that subject (genetic analysis), the lecturer said half of us will fail this subj. ><

hate myself for being sleepy when i really need to concentrate on my studies.
anyone has any suggestion to keep me awake?
coffee - not effective
other junk food - can't concentrate on studies while eating
music - me can only study in complete silence
how how how??!!!